Conventionally, when generating 3D assembly animation using 3D models, a user must define motions one by one for each component making up a product. For example, a digital appliance, a personal computer (PC), or an office device such as a multifunctional machine has several tens to several thousands of components or, in some cases, several tens of thousands of components. The work involved in generating assembly animation of such a product consumes an immense amount of time.
Therefore, technologies exist that automatically generate assembly animation. Conventional techniques recognized as an automatic creating function for assembly animation using 3D models include a technology (1) in which the user defines a motion of each component to generate animation based on the information.
The conventional technology (1) includes a technique of defining the motion of a 3D model based on disassembly definition information set by the user (see, for example, Japanese Patent No. 4291321). The conventional technology (1) also includes a technique of defining motions based on assembly order, component data, and assembly direction data set by the user (see, for example, Japanese Laid-Open Patent Publication No. H8-106486).
Although assembly animation is automatically generated by the conventional technology (1), motions such as the pullout direction and movement amount of a component serving as a basis of the animation must be defined. Therefore, a technology (2) exists in which a system automatically defines the motion of a component to generate animation. The conventional technology (2) includes a technique of using an interference check technique to detect the occurrence of interference for six axes of a coordinate system of a component making up the product so as to determine a disassembly direction based on the interpretation that the component can be disassembled in a direction that causes no interference (see, for example, Japanese Laid-Open Patent Publication No. H10-312208).
Nonetheless, since the interference check is performed in the conventional technology (2), a great deal of time is consumed until a result is obtained. For a product scale (several tens of thousands of components) used in actual operation, an immense amount of computation time is consumed to extract an interference result. Therefore, the conventional technology (2) consumes a great deal of time to extract a result, i.e., to generate animation.
The conventional technology (2) has a problem of low versatility. For example, one product includes a multiplicity of components based on the premise that interference occurs at the time of assembly or in the middle of assembly. In many products, interference generating components such as E-rings, clips, and screws account for 70% or more of the components.
An E-ring or a clip is fit to a shaft component in a direction orthogonal to the axial direction of the shaft component. Therefore, if the E-ring or the clip is pulled out from the shaft component, the E-ring or the clip is pulled out in an orthogonal direction instead of the axial direction and therefore, the E-ring or the clip interferes with the shaft component.
A screw may be designed such that a thread groove is not formed on the shaft of a screw or on the inner surface of a screw hole. In this case, the screw is caused to interfere with the screw hole by making the diameter of the screw shaft larger (or smaller) than the diameter of the screw hole. Since interference is caused by E-rings, clips, and screws accounting for the large portion of components, the conventional technology (2) has a problem the components that can be disassembled are limited.